HEALTH & MEDICINE :: AUGUST/SEPTEMBER 2008
FATS: The Good, The Bad, & The Ugly
Dietary fats have gotten a bad rap for the past 40-plus years. While the low-fat craze did nothing to ameliorate the growing obesity epidemic, the notion that fats are unhealthy has stuck with us at the expense of our health. While certain types of dietary fats are clearly unhealthy, other fats confer many health benefits and may actually promote weight loss. These good fats include the omega-3 polyunsaturated fats, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) found in fish oil, alpha-linolenic acid (ALA) found in flax oil, the omega-6 polyunsaturated fat gamma-linolenic acid (GLA) found in borage, evening primrose, and black currant oils, and monounsaturated fats.
The omega-3 fats EPA and DHA are key ingredients in the membranes of all our body’s cells and comprise a large proportion of our brain and eyes. In addition, they affect hormones which regulate inflammation, blood clotting, and blood pressure. While adequate intake is critical, insufficiencies are increasingly common. Good sources include fatty fish from cold water sources like tuna and salmon, but concerns over mercury intake cause many people to limit their intake of these fatty fish. Plant sources like flaxseed, walnuts, whole grains, and dark leafy greens supply ALA but only a small percentage is converted to the usable forms, EPA and DHA. Moreover, this conversion is reduced by things like alcohol consumption, diabetes, and intake of trans-fats. A good solution is supplementing with high-quality fish oil, one that is tested for heavy metals like mercury and other contaminants. A good starting dose for adults would be 1000mg of combined EPA and DHA daily. Fish oil supplementation in high amounts or in combination with any blood thinners should be done only under a doctor’s supervision.
Omega-6 fats, primarily from vegetable oils, are also essential in the diet. However, high consumption relative to omega-3 intake can actually have a pro-inflammatory effect. Therefore, it is important to balance omega-6 intake with an adequate intake of omega-3’s. An exception to this is GLA which affects compounds that combat excess inflammation. Sources include borage oil, black currant oil, and evening primrose oil. Omega-6 fats should be cold or expeller-pressed as they, like omega-3 fats, can be damaged by heat and light. In addition, less refined omega-6s like sunflower, safflower, and sesame oils are better choices than the more refined corn, soy, and vegetable oils.
Monounsaturated fats including those found in extra-virgin olive oil, various nuts and seeds, and avocados are another family of fats that have been shown to have multiple health benefits and are a healthy and delicious choice.
So what are the bad fats? These include saturated fats from animal sources like meat and dairy. They are the fats that have been linked to elevated cholesterol levels, heart disease, and cancer when ingested in excessive amounts. Although meat and dairy products do contain other important nutrients, they should be consumed in limited amounts due to their saturated fat content. A notable exception to limiting saturated fats is coconut oil. Coconut oil is high in saturated fat but in a form different from the saturated fat from animal sources. Medium-chain triglycerides, the form found in coconuts, are touted to have a wide range of health benefits including germ-fighting and immune support. Interestingly, saturated fats found in human breast milk are in the medium-chain triglyceride form as well.
And now for the ugly: trans-fats. Trans-fats are man-made chemicals found in highly processed foods and have been shown to slow metabolism causing weight gain, increase insulin resistance, increase bad (LDL) while lowering good (HDL) cholesterol, increase triglycerides, and make platelets stickier which may translate into higher risk for heart attack and stroke. These offer no nutritional value and have absolutely no place in our diet. Trans-fats can be found in many margarines and vegetable shortenings, fried foods from restaurants, and processed foods such as crackers, cookies, and breads. If you see “partially hydrogenated” anything on the ingredient list that food contains trans-fats, even if the label states zero grams of trans-fats.
All in all, healthy fats are an important part of a balanced diet. Those seeking to enjoy a health-promoting diet should worry less about the percentage of calories they are taking in as fats and more about the types and relative amounts they are consuming. When adequate dietary intake is difficult, supplementation is a good option. And remember, whenever taking ANY nutritional supplement, those taking prescription medications should ALWAYS check with their doctor and pharmacist as significant and sometimes dangerous drug-nutrient interactions exist.
Dr. Kendall Ritz is board-certified in both Internal Medicine and Pediatrics. She is the Medical Director at Brandywine Center for Integrative Medicine. For more information or to schedule a consultation, contact her office at 302.757.5457 or visit www.brandyintmed.com.
